Introduction

In the previous chapter, I covered the methods of transferring messages over a network using the MAPI calls. This provides a useful way of integrating your VB applications with the mail client and server and makes it very easy to mail-enable any VB application. However, if you want to send mail over any TCP/IP network in particular the Internet or an internal intranet then you need to look to two new mail protocols to do the job. You could carry out the same functionality using MAPI, but you would need to rely on and reconfigure the Exchange client for internal TCP/IP mail and buy and install the Exchange Server software for external links.

In this chapter I cover the ways of sending and receiving messages over a TCP/IP network using the two popular protocols SMTP and POP3. I will be using the suite of Internet controls that was originally supplied by Microsoft as the well-known MS-ICP suite, but is now available from NetMasters. The suite is still called the Internet Control Pack, and provides a range of functions to allow a VB application to establish a TCP/IP session and transfer email using SMTP/POP3. These controls are bundled together as a 32-bit ActiveX control, which is great if you are using one of the newer versions of VB and running the applications under Windows 95 or NT. If you need to develop 16-bit applications, look to the VBX libraries available from Aviary and Crescent and see if these...